A site owner in my site collection created a new Issue Tracking list from the default list template, then added a handful of custom columns from the default list of available column types.
When they try to create an alert, by going to Actions -> Alert Me the When to Send Alerts option only shows Send e-mail immediately without the other email digest options like "Send a daily summary" or "Send a weekly summary" and the time.
I have created a new Issue Tracking list in the same site and the alerts options are all there. I have created a new Issue Tracking list in a different site and all the options are there. I have not recreated the 7 custom columns.
I have poked around in a lot of the list settings, but nothing is standing out. Where should I be looking and what should I be looking for to enable the digest emails?